The time dependence of depolarization currents in diode structures of the metal-dielectric-metal type

Abstract

The depolarization currents of Al-Al2O3-Au and Zr-ZrO2-Au diode structures with oxide thicknesses of D = 5600 A and 700 A were investigated. The depolarization currents were observed after switchoff of the polarizing voltage and removal of the geometric capacitance charges over a lengthy time interval. The direction currents were always opposite in direction to the currents which flowed through the structure under an applied voltage. The functions Idep =f (τ) were recorded at room temperature for various polarizing voltages in air under atmospheric conditions, in a ∼10-4 mm Hg vacuum, and in a vacuum after heating of the structures in a vacuum. It turned out that in the case of the structures investigated in a vacuum after heating in a vacuum, the time dependences of the current under an applied voltage and of the depolarization current were adequately explained by the mechanism of capture by the interior traps of the electrons injected under the action of the field [10]. The mechanism underlying the time dependence of the current in other cases was much more complicated.